JPS61184906A - Ssb demodulation system - Google Patents
Ssb demodulation systemInfo
- Publication number
- JPS61184906A JPS61184906A JP60023646A JP2364685A JPS61184906A JP S61184906 A JPS61184906 A JP S61184906A JP 60023646 A JP60023646 A JP 60023646A JP 2364685 A JP2364685 A JP 2364685A JP S61184906 A JPS61184906 A JP S61184906A
- Authority
- JP
- Japan
- Prior art keywords
- signal
- circuit
- output
- divided
- distortion
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Reduction Or Emphasis Of Bandwidth Of Signals (AREA)
- Mobile Radio Communication Systems (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、伝ばん路で受けた振幅歪を除去するために、
復調部で振幅制限器が用いられるSSB変復調方式にお
ける復調信号に含まれる歪を1除去するための回路方式
に関するものである。[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for removing amplitude distortion received in a propagation path.
The present invention relates to a circuit system for removing distortion included in a demodulated signal in an SSB modulation/demodulation method in which an amplitude limiter is used in a demodulation section.
送信側で音声信号でSSBgi調した後、これに搬送波
を付与して送信信号となし、受信側で信号を受信した後
振幅制限器を用いてその振幅を一定にしてから周波数検
波するごとく構成された通信系においては、復調信号の
歪を小さくするために、SSB信号レベルに比べて搬送
波レベルを大きくする必要があった。After SSBgi modulating the audio signal on the transmitting side, a carrier wave is added to it to make it a transmitted signal, and after receiving the signal on the receiving side, the amplitude is made constant using an amplitude limiter, and then frequency detection is performed. In such communication systems, it was necessary to make the carrier wave level higher than the SSB signal level in order to reduce the distortion of the demodulated signal.
しかし、搬送波は直接情報を伝送していないから、この
ような方式においては、変調信号における情報伝送効率
が低いという欠点があった。However, since the carrier wave does not directly transmit information, such a system has the disadvantage that the information transmission efficiency in the modulated signal is low.
本発明では、これらの欠点を除去するために、復調部で
歪の除去を図るもので、搬送波レベルを大とすることな
く高質な復調信号を得ることのできる復調方式を提供す
ることを目的としている。In order to eliminate these drawbacks, the present invention aims to eliminate distortion in the demodulation section, and an object of the present invention is to provide a demodulation method that can obtain a high-quality demodulated signal without increasing the carrier wave level. It is said that
以下、本発明の構成等に関し、実施例の図面に基づいて
詳細に説明する。Hereinafter, the configuration of the present invention will be described in detail based on the drawings of the embodiments.
第1図は本発明の一実施例のブロック図であって、1は
信号入力端子、2はヒルベルト変換器、3は減算回路、
4は加算回路、5は掛算回路、6は遅延回路、7は加算
回路、8は出力信号端子を表わしている。FIG. 1 is a block diagram of an embodiment of the present invention, in which 1 is a signal input terminal, 2 is a Hilbert transformer, 3 is a subtraction circuit,
4 represents an adder circuit, 5 a multiplication circuit, 6 a delay circuit, 7 an adder circuit, and 8 an output signal terminal.
受信側において、SSB (下側波帯)信号に搬送波を
付加した変調波を受信し、伝ばん路で受けた振幅歪を除
去するために振幅制限器を通してから周波数検波して、
更に、−6dB10ctの等化を行なうことにより原信
号を再生して、この復調信号を第1図の信号入力端子1
に導く。On the receiving side, a modulated wave obtained by adding a carrier wave to an SSB (lower sideband) signal is received, passed through an amplitude limiter to remove amplitude distortion received in the propagation path, and then frequency detected.
Furthermore, the original signal is reproduced by performing equalization of -6dB10ct, and this demodulated signal is sent to the signal input terminal 1 in Fig. 1.
lead to.
そして、該信号は四分割し、その内の一つは、ヒルベル
ト変換器2に導入する。The signal is then divided into four parts, one of which is introduced into the Hilbert transformer 2.
ヒルベルト変換器2の出力は、更に二分割して、入力信
号端子1からの信号との間で減算回路3と加算回路4で
、それぞれ差、および和の信号を作る。減算回路3およ
び加算回路4の出力を入力として掛算回路5で掛算する
。The output of the Hilbert transformer 2 is further divided into two parts, and a subtraction circuit 3 and an addition circuit 4 generate a difference signal and a sum signal between the output signal and the signal from the input signal terminal 1, respectively. The outputs of the subtraction circuit 3 and addition circuit 4 are inputted and multiplied by a multiplication circuit 5.
一方、四分割された入力信号野の内の一つは遅1延回路
6を通って、加算回路7で掛算回路5の出力との和を求
め、これが出力となる。On the other hand, one of the four divided input signal fields passes through the delay circuit 6 and is summed with the output of the multiplication circuit 5 in the addition circuit 7, which becomes the output.
遅延回路6の遅延時間は、出力信号端子8の信号に含ま
れる歪成分が最小になるように決める。The delay time of the delay circuit 6 is determined so that the distortion component contained in the signal at the output signal terminal 8 is minimized.
次に、数式を用いて本発明の動作原理をくわしく説明す
る。Next, the operating principle of the present invention will be explained in detail using mathematical formulas.
まず音声償号惺(1)を
m(t)= f(t) 十j f(t)と解析信号で表
わす。First, the speech compensation equation (1) is expressed as an analytic signal as m(t)=f(t) j f(t).
f(t)はf(t)のヒルベルト変換対である。f(t) is the Hilbert transform pair of f(t).
搬送波角周波数を ω。とすると、S S B信号プラ
ス搬送波出力s (Bは
S (t)= CeO8(IJ ot+ f(t)co
sc+J ot十f(t)sina+ 、t= A c
os (ωot−ω(t) )と書ける。ここで
ω (t) =arctan f(t)/
(C−ト f(t) )である、振幅制限器が用
いられるには、C> If(t)l 、 If(t
)lを満たす必要がある。The carrier angular frequency is ω. Then, S S B signal plus carrier wave output s (B is S (t) = CeO8 (IJ ot + f (t) co
sc+J otf(t)sina+ , t= A c
It can be written as os (ωot-ω(t)). Here ω (t) = arctan f(t)/
(C-t f(t) ), in order to use an amplitude limiter, C> If(t)l , If(t
)l must be satisfied.
振幅制限器出力を周波数検波器に通した出力e(t)は
dω
e (t)=ω。−□
t
この出力を一6dB10atで等化するととなる。DC
成分(ω0)を除いた信号を端子1に導(。The output e(t) obtained by passing the amplitude limiter output through a frequency detector is dω e (t)=ω. -□t If this output is equalized by -6dB10at, then it becomes. D.C.
The signal excluding the component (ω0) is led to terminal 1 (.
従って、端子1での信号成分は、 で1ある。Therefore, the signal component at terminal 1 is There is 1.
ユニで初項−f(t)/ Cが信号の主成分であるから
、これをもとにしてlIp&1図に示した実施例につい
て、動作を説明すると、各信号は、それぞれ、−f(t
)/Cのヒルベルト変換器出力は−f(t)/Cとなり
、減算回路3の出力は(−f(L)/C)十〇(t)/
C)、加算回路4の出力は−((↑(t)/C)+(f
(t)/ C))となる。Since the first term -f(t)/C is the main component of the signal, based on this, the operation of the embodiment shown in FIG.
)/C's Hilbert transformer output is -f(t)/C, and the output of the subtraction circuit 3 is (-f(L)/C) 10(t)/
C), the output of the adder circuit 4 is -((↑(t)/C)+(f
(t)/C)).
この2出力を掛算回路5で演算すると、出力は((f(
t)/ C)−(f(t)/ C))((f(t)/
C)+(fm/ C))= (f(t)/ C)”−(
f(t)/ C)” となる。When these two outputs are calculated by the multiplication circuit 5, the output is ((f(
t)/C)-(f(t)/C))((f(t)/
C)+(fm/C))=(f(t)/C)"-(
f(t)/C)".
この出力を(1)式に加えると
−(f(t)/C)”十〇 (C−’)=(−f(t)
/ C)十〇 (C−コ)となり、2大の歪が除去でき
る。Adding this output to equation (1), -(f(t)/C)"10 (C-')=(-f(t)
/ C) 10 (C-co), and two major distortions can be removed.
遅延回路6は掛算回路5の出力までに信号が種々の回路
を通るために生ずる遅延時間に合うように主信号を遅延
させるもので2次の歪が最小になるように遅延時間を設
定する。The delay circuit 6 delays the main signal to match the delay time caused by the signal passing through various circuits before being output from the multiplication circuit 5, and sets the delay time so that second-order distortion is minimized.
なお、上述の説明に用いた数式からも明らかなように、
本発明と同等の機能の実現手段として、復調信号を二乗
した信号と該復調信号をヒルベルト変換した信号を二乗
した信号との差の信号と、前記復調信号を一定時間遅延
せしめた信号とを加算することにより出力を得る構成を
採ることもできる。Furthermore, as is clear from the formula used in the above explanation,
As a means for realizing a function equivalent to that of the present invention, a signal representing the difference between a signal obtained by squaring a demodulated signal and a signal obtained by squaring a signal obtained by Hilbert-transforming the demodulated signal, and a signal obtained by delaying the demodulated signal by a certain period of time are added. It is also possible to adopt a configuration in which output is obtained by doing this.
しかし、一般に掛算回路(二乗は掛算回路で行なう)は
、構成が複雑であって、特にそれを上述の構成のように
複数組設けた場合には、各掛算回路の特性の差を補償す
るための整合等が必要となり取り扱いが極めて繁雑とな
るうえ、良好な結果が期待できない。However, multiplier circuits (squaring is performed by the multiplier circuit) generally have a complex configuration, and especially when multiple sets are provided as in the above configuration, it is necessary to compensate for differences in the characteristics of each multiplier circuit. It is extremely complicated to handle as it requires matching, etc., and good results cannot be expected.
不発明は、実施例にも見られるように、掛算回路は1組
設けるのみで良く、従って、取り扱いが容易で良好な特
性を有する回路を実現し得るものである。The advantage of the present invention is that, as seen in the embodiments, only one set of multiplication circuits is required, and therefore a circuit that is easy to handle and has good characteristics can be realized.
以上説明したように、本発明の方式によれば、再1生信
号に含まれる歪を除去することが可能で、特に、聰感上
耳ざわりになる原音の2倍の周波数成分を除去すること
ができるから、復調音声品質が改善される。また、歪除
去回路がない場合には搬送波レベルを高めることによっ
て復調音声の歪率を低くしなければならなかったが、本
発明の方式によれば、従来のように搬送波レベルを高(
する必要がないから、情報伝送効率を高めることができ
る利点がある。As explained above, according to the method of the present invention, it is possible to remove the distortion contained in the reproduced signal, and in particular, it is possible to remove the frequency component twice that of the original sound, which is harsh on the ears. As a result, demodulated audio quality is improved. Furthermore, in the absence of a distortion removal circuit, it was necessary to lower the distortion rate of demodulated audio by increasing the carrier wave level, but according to the method of the present invention, the carrier wave level is raised (
Since there is no need to do this, there is an advantage that information transmission efficiency can be increased.
第1図は、本発明の一実施例のブロック図である。 FIG. 1 is a block diagram of one embodiment of the present invention.
Claims (1)
付与して送信信号となし、受信側で信号を受信した後、
振幅制限器を用いてその振幅を一定にしてから周波数検
波するごとく構成された通信系において、復調信号と該
復調信号をヒルベルト変換して得た信号との和および差
を求め、該和の信号と差の信号とを掛算して得た信号と
、前記復調信号を一定時間遅延せしめた信号とを加算す
ることにより出力を得ることを特徴とするSSB復調方
式。After SSB modulation with the audio signal on the transmitting side, a carrier wave is added to it to make it a transmitted signal, and after receiving the signal on the receiving side,
In a communication system configured to use an amplitude limiter to make the amplitude constant and then perform frequency detection, the sum and difference of the demodulated signal and the signal obtained by Hilbert transformation of the demodulated signal are calculated, and the sum signal is An SSB demodulation method characterized in that an output is obtained by adding a signal obtained by multiplying a signal by a difference signal and a signal obtained by delaying the demodulated signal by a certain period of time.
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2364685A JPH0740642B2 (en) | 1985-02-12 | 1985-02-12 | SSB demodulation circuit |
EP85308784A EP0184923B1 (en) | 1984-12-10 | 1985-12-03 | Single-sideband communication system |
DE8585308784T DE3585502D1 (en) | 1984-12-10 | 1985-12-03 | SINGLE-SIDED TAPE TRANSFER SYSTEM. |
US06/806,991 US4803739A (en) | 1984-12-10 | 1985-12-09 | SSB communication system |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2364685A JPH0740642B2 (en) | 1985-02-12 | 1985-02-12 | SSB demodulation circuit |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS61184906A true JPS61184906A (en) | 1986-08-18 |
JPH0740642B2 JPH0740642B2 (en) | 1995-05-01 |
Family
ID=12116317
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2364685A Expired - Lifetime JPH0740642B2 (en) | 1984-12-10 | 1985-02-12 | SSB demodulation circuit |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0740642B2 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2009097924A (en) * | 2007-10-15 | 2009-05-07 | Denso Corp | Apparatus for detecting rotation angle |
-
1985
- 1985-02-12 JP JP2364685A patent/JPH0740642B2/en not_active Expired - Lifetime
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2009097924A (en) * | 2007-10-15 | 2009-05-07 | Denso Corp | Apparatus for detecting rotation angle |
Also Published As
Publication number | Publication date |
---|---|
JPH0740642B2 (en) | 1995-05-01 |
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